1. Field of the Invention
The invention relates to a supporting structure of a multiple-plate clutch which is used for an automatic transmission and a method of assembling the multiple-plate clutch and a shaft with a pump cover.
2. Related Background Art
Generally, according to a multiple-plate clutch which is used for a gearbox of a vehicle, a bearing or a bush for executing a bearing operation in the radial direction is interposed between an inner cylindrical portion of a clutch drum and a shaft, a thrust washer is further interposed between a bottom wall portion of the clutch drum and a partner member, and the clutch is supported to the shaft and the partner member.
For example, Japanese Utility Model Application Laid-Open No. 2-103567 discloses a supporting structure for supporting a drum of a frictional engaging apparatus through a bush and discloses a construction in which the bush is attached to a member which faces an inner cylindrical portion on an outer peripheral side of the inner cylindrical portion of the drum and the inner cylindrical portion is supported by the bush from the outer peripheral side.
Japanese Patent Application Laid-Open No. 2-146343 discloses a supporting structure of a clutch of an automatic transmission in which it has a cylindrical shaft member for supporting a cylindrical portion of an inner cylinder of a clutch drum, the shaft member is further supported to another shaft member, and a fulcrum arranged in an inner peripheral portion of the cylindrical shaft member and a fulcrum for supporting an inner peripheral portion of the inner cylinder of the clutch drum arranged on an outer peripheral side are arranged at a same position in the axial direction.
In Japanese Utility Model Application Laid-Open No. 2-103567 and Japanese Patent Application Laid-Open No. 2-146343 mentioned above, the supporting structure in which the bearing or bush for executing the bearing operation in the radial direction is interposed between the inner cylindrical portion of the clutch drum and the shaft and the thrust washer is interposed between the bottom wall portion of the clutch drum and the partner member is shown as a structure of the multiple-plate clutch.
In consideration of assembling performance, precision of parts, and the like, the multiple-plate clutch is attached in the state where it is movable in the axial direction by a distance of about 2 mm by summing clearances between other parts in a mission casing. Therefore, even with a member such as a thrust washer or the like as mentioned above which is interposed in the axial direction, in the case where a position of the center of gravity in the axial direction of the whole multiple-plate clutch is out of a range in the width direction of the bearing or bush executing the bearing operation in the radial direction, an inclination occurs in the multiple-plate clutch. Such an inclination applies a local load to the bearing or bush executing the bearing operation in the radial direction, so that seizure occurs and a judder or an abnormal sound is caused upon frictional engagement of the multiple-plate clutch.